I don't want to presume too much on the part of the author, but this seems like pretty blatant self-insert wish fulfillment. The MC without friends who most people would call a creepy otaku gets swept off her feet by a popular, energetic sports star who fell in love with her at first sight.
That said, the fact that I can recognize it as such indicates that both my scenario and my wish aren't all that far off, so maybe I don't have room to speculate.